Why do we need 2 different fruit trees?

I often hear folks say they need a male apple tree

variety to pollinate their female tree so they can have

fruit. This is partially correct I suppose, but male vs

female is not really the point.

The pollen of most fruit trees is self-sterile. This

means that these trees may pollinate a different genotype

but not the same variety of tree. For example, Granny Smith

apple pollen may pollinate Fuji flowers and vice versa.

Both will generate fruit.

Many fruit trees and shrubs are like this. Even in the

wild they are, but we don’t realize it. There is never an

issue about wild blueberries for example. This is because

the plants are likely seedlings, and all have a different

genotype. Any plant that reproduces sexually might have

similar characteristics as its parents or siblings, but all

plants will be genetically different. Therefore, they may

pollinate with any surrounding plant of the same species.

This concept is important when you are purchasing

trees for your orchard. Unless there are other fruit trees

nearby, you must buy two different varieties of the same

type of fruit, or you will get none.

Pecans are like this, but nobody realizes it. There

are so many volunteer pecan trees around that there is

almost always adequate pollen available to satisfy all the

flowers.

Sometimes there are separate male and female trees,

and in this case, both must be present to get fruit. The

American persimmon is a good example here. The entire tree

is either male or female unless it has been grafted with

the opposite sex which is not a common practice. The non-

astringent Fuyu persimmon is an exception. It is self-

fertile.

Ginkgo trees are dioecious also, meaning the trees are

totally male or totally female. Anyone who has ever had

ginkgo trees in the neighborhood knows how fetid female

ginkgo trees can smell. That’s one reason that so many in

the nurseries are grafted.

Hollies are also entirely male or entirely female, so

you need to keep that in mind when planting them. An

exception is the Nellie R. Stevens holly. It can produce

fruit without pollination through a process called

parthenogenesis. That is why they all seem to have berries

on them. However, there is a related cultivar, a male one

called Edward J. Stevens, which will cause fruit set to be

even higher.

Many trees and vegetable plants have separate male

flowers on the same plant. Good examples are cucumbers,

cantaloupes, watermelons, pumpkins, and squash. Some people

can’t understand why they have so many flowers but no

fruit. That is likely because most of the flowers,

especially the early ones, are all male flowers. Be patient

and you will get your fruit.